Spray nozzle

ABSTRACT

A nozzle comprising a swirl chamber having an exit port for discharging a whirling conical spray. The swirl chamber is supplied with fluid through a fluidic switch which in turn is controlled by conditions in the swirl chamber in such fashion as to periodically disrupt the whirling action and alter the spray pattern discharged from the exit port.

United States Patent Fichter Dec. 4, 1973 [5 SPRAY NOZZLE 3,510,112 5/1970 Winquist et al 239/101 X 3,267,946 8/1966 Adams et al.... 137/813 [75] Barry Flchte" Dunellen 3,595,479 7 1971 Freeman 239 102 [73] Assignee: American Standard Inc., New York, 3,509,775 5/1970 Evans 137/829 X N.Y. Primary Examiner-M. Henson Wood, Jr. [22] Filed' June 1972 Assistant Examiner-John J. Love [21] A 1. No.: 259,649 AttorneyJohn E. McRae et al.

[52] US. Cl 239/101, 239/102, 239/474, [57] ABSTRACT 239/478, 137/813 51 Int. Cl B05b 1/08, B05b 1/34 A male a chamber havmg an [58] Field 01 Search 239/101 102 464 P r discharging a whirling conical Spray The Swirl 239/472 478 474 477 5 chamber is supplied with fluid through a fluidic switch which in turn is controlled by conditions in the swirl chamber in such fashion as to periodically disrupt the [56] References Cited whirling action and alter the spray pattern discharged UNITED STATES PATENTS mm the 553,727 1 1896 Van Sickle 239/474 5 Claims, 2 Drawing Figures f 25 50 i Q\ I 22 1 I 21 Q fi 26 1 "I 19 30 24 l f [O f Z0 Z7 1 I I I SPRAY NOZZLE BACKGROUND OF THE INVENTION Field of the Invention This invention relates generally to fluidic devices requiring no moving mechanical parts for the operation thereof and, more particularly, to a fluidic oscillator and whirl chamber for forming a pulsating conical stream. The invention has potential application in such fields as lawn sprinklers, shower bath spray heads, washing machine spray units, whirlpool baths, decorative fountains, fog horns, paint Sprayers, and mouth pieces for wind instruments.

SUMMARY OF THE INVENTION In the field of fluidics the direction taken by a power stream can be controlled by interracting control jets connected to the fluid zone immediately downstream from the power stream nozzle. By varying or controlling the relative strengths of the control jets it is possible to selectively cause the power stream to attach to different ones of the divergent wall surfaces forming the nozzle outlet chamber. In this manner it is possible to control or switch the path taken by the power stream.

In the present invention the path taken by the power stream is controlled or varied by pressure resistances periodically generated in the nozzle outlet chamber. These pressure resistances reduce the velocity of the flowing stream and its ability to attach onto one of the divergent nozzle wall surfaces; the slowly moving fluid does not produce a sufficient vacuum force on the attaching wall to maintain the attachment. As a result, the power stream is caused to at least partially detach from the wall and thereby change direction. In one illustrative embodiment of the invention the directional changes are cuased to take place at a rate of about 200 times per minute, whereby the fluid output takes on a pulsating or oscillating character.

When the invention is employed in a liquid spray device, for example a shower head, the output from the fluidic switch is selectively directed through two paths to a vortex swirl chamber having a nozzle discharge opening in one of its end walls. In one mode of operation the liquid power stream enters the swirl chamber in a tangential direction, thereby generating a swirling liquid flow that is centrifugally exhausted through the nozzle discharge opening as a relatively wide angle conical spray. In another vmode of operation the liquid power stream enters the swirl chamber in a generally radial direction, thereby generating a lessened swirl in the chamber; the liquid exits from the chamber as a relatively narrow angle conical spray.

The relationship of the fluidic switch and swirl chamber is such that the conical discharge spray oscillates rapidly between the wide angle cone pattern and the narrow angle cone pattern, for example at an oscillating frequency of about 200 cycles per minute.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view taken on line 1-1 in FIG. 2 and illustrating a structure in accordance with the invention; and,

FIG. 2 is a sectional view on line 22 in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the FIGS. 1 and 2, there is illustrated a shower spray nozzle 8 for generating a pulsating conical stream of fluid from a nonpulsating stream of supply fluid, the divergence or cone angle of the pulsating stream being varied in an oscillating fashion. Nozzle structure 8 comprises two wall members 9 and 11 suitably secured together, as by screws or adhesives (not shown) to define a water passage system. Wall member 11 takes the form of a flat plate. Wall member 9 takes the form of a thickened block having a lower flat face sealingly engaged with the upper face of wall 11; recesses are formed in block 9 to define the water passage system.

Water supply member 10 has a rotary fit in a circular cavity 13 in block 9, whereby nozzle structure 8 can be manually rotated around the axis of member 10 while maintaining a water flow connection between the supply passage 15 and fluidic nozzle 17.

Nozzle 17 comprises two divergent wall surfaces 18 and 20 which cooperatively define a switching chamber 22. Positioned within the switching chamber is an adjustable flow diverter partition 24 of generally triangular plan cross section; the partition subdivides chamber 22 into two separate flow passages 25 and 27. A pivot pin 26 is affixed to the partition and to an external actuating knob 28, the arrangement being such that manual rotation of the knob causes the tip area 30 of partition 24 to move toward or away from nozzle surface 18, thereby effectively varying the size of passage 25.

Wall surface 18 is connected to one edge of the main nozzle port 19 by a lateral wall surface 21; wall surface 20 connects directly with the other edge of nozzle port 19. A small atmospheric air passage 23 connects with surface 20 near the point where surface 20 joins port 19.

Assuming minimum flow resistance in passages 25 and 27, the water discharging through port 19 will attach to surface 18 and thus flow through passage 25; little or no fluid will flow through passage 27. The step or offset at 21 provides a potential low-pressure zone along wall surface 18, while no such low pressure zone is formed along surface 20 because atmospheric passage 23 permits air to be drawn into the zone alongside surface 20 to thereby maintain a relatively high pressure condition. The relatively low pressure on surface 18, coupled with the relatively high pressure on surface 20, causesthe mainstream fluid to attach to wall surface 18. I

Should a back pressure be developed in passage 25 the fluid will flood space 22, and the flow rate along surface 18 will be reduced. The reduced flow rate will have a lessened capability for producing a vacuum force on wall surface 18 so that the flowing stream will at least partly detach from surface 18. Under such conditions the fluid will divide between passages 25 and 27; i.e., part of the fluid will flow through passage 25 and the remainder will flow through passage 27.

The structure thus far described constitutes a fluidic switch having an oscillating output manifested as a periodic change in the flow pattern, between an attached mode confined to passage 25 and a detached mode apportioned to passages 25 and 27. In one embodiment of the invention an oscillation between the two modes was achieved at a frequency of about 200 cycles per minute.

Passage 25 of the described fluidic switch tangentially connects to a vortex swirl chamber 34 of generally circular contour. Passage 27 connects to the swirl chamber 34 along a radial or chord-like direction opposing the direction of swirl designated by numeral 50. When the fluid flow is confined to passage 25 the fluid enjoys a circumferential swirling motion 50 in chamber 34; eventually the fluid exits through the circular discharge port 36 as a spiralling conical spray having a relatively wide cone angle designated by letter A. When the fluid flow is divided between passages 25 and 27 the swirl in chamber 34 is at least partially removed so that the fluid issues from port 36 as a relatively narrow cone angle spray designated by letter B.

The change between the spiralling wide angle spray mode and the non-spiralling narrow angle spray mode is effected by pressure changes that automatically occur during operation of the device. Assume for example that all of the fluid enters vortex chamber 34 through tangential passage 25 and exits from outlet port 36 as a spinning conical spray. Under this condition, the flow is spinning or whirling rapidly in vortex chamber 34, so that eventually the resultant centrifugal forces build up a back pressure to a value where the flow of fluid through passage 25 is throttled to cause chamber 22 to flood; the whirling action in chamber 34 keeps the fluid in the chamber for a prolonged time instead of permitting it to rapidly exhaust through port 36. Accordingly, passage 25 tends to trap the flowing stream to produce the back pressure effect.

The resultant flooding in space 22 destroys the attachment of the fluid jet on wall 18. The fluid flow then divides substantially equally through the tangential passage 25 and the radial passage 27. At this instant, the flow of fluid through tangential passage 25 is reduced, and the flow of fluid through radial passage 27 mixes with the fluid flowing around vortex chamber 34 to further reduce the rotating velocity of the fluid in the vortex chamber to effectively decrease the centrifugal pressure forces and increase the total flow through port 36. Chamber 22 is thereby at least partially drained, and the fluid jet reattaches itself to wall 18 to start a new cycle.

During the period of the cycle when the fluid jet stream becomes detached from wall 18 the exit flow from outlet port 36 has a pattern which is not as divergent as the pattern achieved when the flow is attached to wall 18. The fan-out or divergence of the fluid flow issuing from outlet port 36 can be controlled by turning knob 28 to move the tip area 30 toward or away from wall 18. When tip area 30 is adjusted closer to wall 18, it will divert more fluid through passage 27 during the non-swirl mode of operation. Accordingly the spray pattern will tend to oscillate essentially between the relatively narrow cone spray pattern B and the essentially solid jet stream C.

The illustrated pattern angles A, B and C are approximately representative of the angles obtained in actual practice. The actual patterns are influenced by the size of port 36 and the contour of the deflector surface 38. When deflector surface 38 is not used the spray tends to have a wider angle than that illustrated in the draw- The spray angle also tends to be influenced by the position of diverter plate 40. When the plate is adjusted toward port 36 the narrow pattern tends to be more divergent; i.e., to resemble pattern B rather than pattern C.

The oscillation frequency (number of switches in spray pattern angle per unit time period) is affected by several factors, including the fluid supply pressure and the size of port 36. In general the frequency tends to be higher as the supply pressure is increased and port 36 is made larger (within limits).

As previously noted, the oscillatory change in spray cone angle is believed to be caused by instantaneous pressure changes occurring in and/or near the whirl chamber. Using a conventional pressure transducer and electrical read-out equipment, I have been able to obtain a pen-chart record of instantaneous pressures in the whirl chamber. These pressure readings show cyclic pressure changes ranging from 60 to 750 cycles per minute. Since the spray oscillation frequency is believed to vary directly with the frequency of the pressure change, the readings are interpreted as an indication of spray oscillation frequencies in the 60-750 cycle per minute range. It is believed that lower frequencies, possibly as low as 10 cycles per minute, could probably be obtained by choice of parameters and some experimentation.

Preferably the device is formed to include the illustrated circular island 42. Apparently this island helps to guide and define the vortical flow to achieve a more pronounced pulsation or oscillation. The island may possibly act as a flow interrupter or backstop to promote energy interchange between the fluid coming from passage 27 and the swirling fluid, thus producing a more effective disturbance of the swirl during switchover from the wide spray mode A to the narrow spray mode B.

When the invention is used in showerhead applications the atmospheric passage 23 may have some incidental advantage as an aeration mechanism. Thus, the air that is drawn through passage 23 mixes with the water particles to provide a partially aerated stream; a plug valve 55 may be provided to control the aeration efi'ect and the magnitude of the pulsation. When plug valve 55 is closed off, the pulsations cease, and the flow from the shower emerges as cone C. Additional aeration ports 44 may be provided in island 42 or other areas of the device.

In the showerhead application the invention provides a pulsating flow that gives a physical sensation somewhat akin to hydrotherapy. The pulsating action is also beneficial in that it provides greater coverage to the sprayed areas. Thus, instead of a hollow spray cone (as is achieved with many arrangements) this device covers both the outer annular spray area (pattern A) and the inner central spray area (pattern B or C).

The device operates over a relatively wide range of supply pressures, from about 4 p.s.i. up to more than p.s.i.

Work to date has been mostly confined to water spray noule structures, but it is believed that the invention might also be embodied in other structures, such as paint sprayers and foghoms. An air-operated device has been built and tested and provides performance similar to that of the water-powered device.

1 claim:

1. A spray device comprising:

a fluidic switch having a nozzle opening, and first and second guide walls extending from the opening in divergent relationship to guide the fluid after its discharge from said opening; the first guide wall being connected to the nozzle opening in such fashion that said wall functions as an attachment surface for the nozzle fluid; the second guide wall hav- 5 ing an atmospheric port adjacent said opening, whereby said second guide wall is precluded from acting as a fluid attachment surface;

and a vortex chamber located to receive fluid from the first and second guide walls; said first guide wall having a tangential connection with the vortex chamber to promote a swirling condition therein; said second guide wall having a connection with the swirl chamber whereby fluid flowing along said second wall tends to obstruct the swirling movement as the fluid flows into the chamber;

said vortex chamber having an axially oriented port operable to discharge fluid from the chamber; said discharge port being sized to produce a back pressure in the vortex chamber when the chamber fluid is in a swirling condition, whereby the fluid floods the zone defined by the divergent guide walls, thereby producing a swirl-disrupting flow along the second guide wall; the flow area defined by the divergent guide walls being sufficient that continued flow thereacross rapidly restores the swirling condition in the vortex chamber, whereby the fluid output from the discharge port takes the form of an oscillating output of varying cone angle.

2. The device of claim 1 wherein the components are constructed to provide an oscillating output having a frequency between about and 750 cycles per minute.

3. The device of claim 1 wherein the vortex chamber is provided with an axially oriented circular island having a surface in registry with the flow path defined by the second guide wall to promote interaction between the swirling fluid and the swirl-obstruction fluid.

4. The device of claim 1 wherein the first guide wall connects to one edge of the nozzle opening by means of an offset wall that provides a low pressure zone along the surface of the first guide wall.

5. The device of claim 4 wherein the aforementioned atmospheric port operates without variation in size during the oscillating cycle. 

1. A spray device comprising: a fluidic switch having a nozzle opening, and first and second guide walls extending from the opening in divergent relationship to guide the fluid after its discharge from said opening; the first guide wall being connected to the nozzle opening in such fashion that said wall functions as an attachment surface for the nozzle fluid; the second guide wall having an atmospheric port adjacent said opening, whereby said second guide wall is precluded from acting as a fluid attachment surface; and a vortex chamber located to receive fluid from the first and second guide walls; said first guide wall having a tangential connection with the vortex chamber to promote a swirling condition therein; said second guide wall having a connection with the swirl chamber whereby fluid flowing along said second wall tends to obstruct the swirling movement as the fluid flows into the chamber; said vortex chamber having an axially oriented port operable to discharge fluid from the chamber; said discharge port being sized to produce a back pressure in the vortex chamber when the chamber fluid is in a swirling condition, whereby the fluid floods the zone defined by the divergent guide walls, thereby producing a swirl-disrupting flow along the second guide wall; the flow area defined by the divergent guide walls being sufficient that continued flow thereacross rapidly restores the swirling condition in the vortex chamber, whereby the fluid output from the discharge port takes the form of an oscillating output of varying cone angle.
 2. The device of claim 1 wherein the components are constructed to provide an oscillating output having a frequency between about 60 and 750 cycles per minute.
 3. The device of claim 1 wherein the vortex chamber is provided with an axially oriented circular island having a surface in registry with the flow path defined by the second guide wall to promote interaction between the swiRling fluid and the swirl-obstruction fluid.
 4. The device of claim 1 wherein the first guide wall connects to one edge of the nozzle opening by means of an offset wall that provides a low pressure zone along the surface of the first guide wall.
 5. The device of claim 4 wherein the aforementioned atmospheric port operates without variation in size during the oscillating cycle. 